Vane compressor

ABSTRACT

Provide a vane compressor which starts the compression without delay, and which prevents the vanes from chattering under the start-up operation. To this end, the vane compressor  1  includes: a cylinder chamber  3 ; a rotor  5  rotatably arranged in the cylinder chamber  3 ; vane grooves  7  provided in the rotor  5  at equal intervals in the circumferential direction thereof; vanes  9  arranged in the vane grooves  7  in a way that the vanes  9  are capable of protruding to, and retracting from, the cylinder chamber  3 ; and the vane back-pressure chamber  11  communicating with the bottom portions of the vane grooves  7 , and configured to apply the back pressure to the vanes  9 ; and a back-pressure supplying unit  13  configured to transmit the pressure to the vane back-pressure chamber  11 , and to push up the vanes to the sliding surface of the cylinder chamber  3  once the activation mode for rotating the rotor  5  is selected.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a vane compressor with a compressionchamber being formed in a cylinder chamber by use of vanes whichprotrude out of a rotor.

2. Description of the Related Art

An example of a current type of vane compressor is disclosed in JapanesePatent Application, Laid-Open No. 2004-190509. In this type of vanecompressor, when a rotor rotates, a centrifugal force and a backpressure stemming from a discharge pressure raise the vanes in the vanegrooves up until the vanes come into intimate contact with the slidingsurface of a cylinder chamber. Thereby, the vane compressor starts tocompress the gas. For the purpose of facilitating the movement andintimate contact of the vanes under start-up operation, the vanecompressor is provided with a volute pump driven by the rotation of therotor. This volute pump transmits the back pressure to a vaneback-pressure chamber.

Only after the compressor is activated, the volute pump starts torotate, and the discharge pressure of the compressor starts to rise.There is a time lag between the activation of the compressor and theactual compression which starts with the application of a desired backpressure to the vane back-pressure chamber. Because of this, the realcompression lags behind.

On the other hand, once the compressor stops its operation, the vanessometimes retract to the bottom portions of the vane grooves due to thegravitation and the differential pressure generated by the reverserotation of the rotor. This is because the discharge pressure and thevane back pressure generated by the volute pump disappear. Once thecompressor is activated again under this state, the vanes repeatedly hitthe cylinder chamber during their incomplete compression and dischargestrokes due to a centrifugal force until a stable pressure is suppliedto the vane back-pressure chamber. This causes the vanes to chatterunder the start-up operation, and accordingly causes continuousimpulsive sounds.

In the case of the vane compressor using the pressure generated by thevolute pump and the discharge pressure of itself, as described above,the vane back pressure starts to rise only after the compressor isactivated. For this reason, the start of real compression lags theactivation of the compressor more, and the vanes continue to chatterunder the start-up operation for a longer time.

SUMMARY OF THE INVENTION

The present invention has been made with the foregoing problem takeninto consideration. An object of the present invention is to provide avane compressor which causes the compression to start without delay, andwhich prevents the vanes from chattering under its start-up operation.

A first aspect of the present invention is a vane compressorcharacterized by including: a cylinder chamber; a rotor rotatablyarranged in the cylinder chamber; vane grooves provided in the rotor atequal intervals in the circumferential direction of the rotor; vanesarranged in the respective vane grooves in a way that the vanes arecapable of protruding to, and retracting from, the cylinder chamber; avane back-pressure chamber communicating with the bottom portions of therespective vane grooves, and configured to apply a back pressure to thevanes; and a back-pressure supplying unit configured to push up thevanes to the sliding surface of the cylinder chamber by transmitting theback pressure to the vane back-pressure chamber when an activation modefor rotating the rotor.

In the vane compressor according to the first aspect, once theactivation mode is selected, the back-pressure supplying unit transmitsthe back pressure to the vane back-pressure chamber, as well as thevanes are thus pushed up to, and brought into intimate contact with, thesliding surface of the cylinder chamber, before the rotor starts torotate. For this reason, the start of real compression does not lag theactivation of the compressor, unlike the vane compressor of the currenttype in which a pressure starts to be applied to the vane back-pressurechamber after the rotor starts to rotate. As a result, the compressor isno sooner activated than the compression starts. This increases thecompression performance.

In addition, the rotor starts to rotate only after the vanes are at oncepushed up to, and brought into intimate contact with, the slidingsurface of the cylinder chamber due to the pressure supplied by theback-pressure supplying unit. For this reason, the vanes no longerchatter as a consequence of repeated hit of the vanes against thecylinder chamber under the start-up operation.

A second aspect of the present invention is the vane compressoraccording to the first aspect, characterized in that the back-pressuresupplying unit includes: a back-pressure cylinder communicating with thevane back-pressure chamber; an activation piston configured to generatethe back pressure by moving in the back-pressure cylinder; an activationspring configured to bias the activation piston in a direction in whichthe back pressure is generated (hereinafter referred to as a“back-pressure generating direction”); and a position holding moduleconfigured to hold the activation piston in its resting position againstthe activation spring.

In the vane compressor according to the second aspect, once theactivation mode is selected, the activation piston is released from theposition at which the activation piston has been held by the positionholding module, and the activation spring thus moves the activationpiston in the back-pressure generating direction of the cylinder.Thereby, the back pressure is supplied to the vane back-pressurechamber, and brings the vanes into intimate contact with the slidingsurface of the cylinder chamber.

A third aspect of the present invention is the vane compressor accordingto the second aspect, characterized in that the position holding moduleincludes: an engagement part provided between the activation piston anda stopper member, and configured to hold the activation piston in itsresting position; an engagement spring configured to bias the stoppermember in an engagement direction of the engagement part; and anelectromagnetic solenoid configured to release the engagement part fromits engagement against the engagement spring.

In the vane compressor according to the third aspect, the engagementspring holds the engagement part in the holding condition until theactivation mode is selected. Once the activation mode is selected, theelectromagnetic solenoid moves the stopper member against the engagementspring, and thus releases the engagement part from the engagement.Thereby, the activation spring moves the activation piston in theback-pressure generating direction, and the back pressure is thussupplied to the vane back-pressure chamber. The back pressure brings thevanes into intimate contact with the sliding surface of the cylinderchamber.

Furthermore, the electromagnetic solenoid is operated only a moment atwhich the engagement part is released from the engagement by moving thestopper member. For this reason, the electromagnetic solenoid consumesonly a very small amount of electric power.

A fourth aspect of the present invention is the vane compressoraccording to the third aspect, characterized in that: the activationpiston is provided with a cam configured to cause the stopper member toretract against the engagement spring when the activation pistonretracts due to a return pressure which is transmitted from the vaneback-pressure chamber after the completion of the activation thereof;and the engagement spring is that configured to cause the engagementpart to engage by pressing the stopper member once retracted.

In the vane compressor according to the fourth aspect, after thecompletion of the activation, the activation piston and the activationspring as well as the engagement spring and the engagement part of theposition holding module are automatically reset in their respectiveresting positions where they rest before the activation mode is selectedin accordance with the following scheme. That is because, when theactivation piston retracts to its resting position side with the returnpressure being applied from the vane back-pressure chamber, the camprovided to the activation piston causes the stopper member to retractagainst the engagement spring in the middle of its retraction.Subsequently, the engagement spring presses the stopper member onceretracted, and thus causes the engagement part to engage.

A fifth aspect of the present invention is the vane compressor accordingto any one of the second to fourth aspects, characterized in that thelow-pressure side of the back-pressure cylinder communicates with theinlet port.

In the vane compressor according to the fifth aspect, the low-pressureside of the back-pressure cylinder communicates with the inlet port. Forthis reason, after the completion of the activation, when the activationpiston returns to its resting position side with the return pressurebeing applied from the vane back-pressure chamber, the activation pistonis assuredly returned to its resting position by the suction effect ofthe low pressure coming from the inlet port.

A sixth aspect of the present invention is the vane compressor accordingto the first aspect, characterized in that the back-pressure supplyingunit includes: a high-pressure tank communicating with the vaneback-pressure chamber, and filled with a highly-pressurized fluid; avalve configured to allow and shut off the flow of the fluid between thevane back-pressure chamber and the high-pressure tank; anopening/closing module configured to open the valve, and thus to causethe back pressure to be transmitted from the high-pressure tank to thevane back-pressure chamber, once the activation mode is selected.

In the vane compressor according to the sixth aspect, once theactivation mode is selected, before the rotor starts to rotate, thevalve opens the high-pressure tank, and the back pressure is thustransmitted to the vane back-pressure chamber. Thereby, the vanes arepushed up, and brought into intimate contact with, the sliding surfaceof the cylinder chamber. For this reason, the start of real compressiondoes not lag the activation of the compressor. As a result, thecompressor is no sooner activated than the compression starts. Thisincreases the compression performance.

In addition, the rotor starts to rotate only after the vanes are at oncepushed up to, and brought into intimate contact with, the slidingsurface of the cylinder chamber due to the pressure coming from thehigh-pressure tank. For this reason, the vanes no longer chatter as aconsequence of repeated hit of the vanes against the cylinder chamberunder the start-up operation.

Furthermore, only immediately after the activation mode is selected, theelectromagnetic solenoid needs to be operated. For this reason, theelectromagnetic solenoid consumes only a very small amount of electricpower.

A seventh aspect of the present invention is the vane compressoraccording to the sixth aspect, characterized in that the opening/closingmodule includes: a stopper spring configured to close the valve; and anelectromagnetic solenoid configured to cause the back pressured to betransmitted from the high-pressure tank to the vane back-pressurechamber by opening the valve against the stopper spring once theactivation mode is selected.

In the vane compressor according to the seventh aspect, before theactivation mode is selected, the valve is stopped by the stopper spring.Once the activation mode is selected, the electromagnetic solenoidreleases the valve against the stopper spring, and the back pressure isthus transmitted to the vane back-pressure chamber.

Moreover, the valve is configured in such a way as to be releasedagainst the stopper spring. For this reason, once the vane compressorstarts a compression operation, the valve is released against thestopper spring with the return pressure being applied from the vaneback-pressure chamber, and the high-pressure tank is thus filled withthe oil. Additionally, once the internal pressure of the high-pressuretank becomes equal to the pressure of the vane back-pressure chamber,the valve is stopped by the stopper spring, and is thus reset to itsresting position at which the valve is located before the activationmode is selected.

In this manner, the valve can be reset to the resting position withoutuse of an external force or electric power.

In addition, the valve is reset to the resting position withoutoperating the electromagnetic solenoid. All the more for this, theelectromagnetic solenoid saves its power consumption.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 shows a first embodiment, and is a configuration diagram of achief section of a vane compressor which is put in a resting conditionbefore an activation mode is selected.

FIG. 2 shows the first embodiment, and is a configuration diagram of thechief section of the vane compressor in which a back pressure is beingtransmitted to a vane back-pressure chamber after the activation mode isselected.

FIG. 3 shows the first embodiment, and is a configuration diagram of thechief section of the vane compressor in which a back-pressure supplyingunit and a position holding module are reset after a compressionoperation starts.

FIG. 4 shows a second embodiment, and is a configuration diagram of achief section of a vane compressor which is put in a resting conditionbefore an activation mode is selected.

FIG. 5 shows the second embodiment, and is a configuration diagram ofthe chief section of the vane compressor in which a back pressure isbeing transmitted to a vane back-pressure chamber after the activationmode is selected.

FIG. 6 shows the second embodiment, and is a configuration diagram ofthe chief section of the vane compressor in which a back-pressuresupplying unit and an opening/closing module are reset after acompression operation starts.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Descriptions will be provided hereinbelow for the embodiments of thepresent invention by referring to the drawings.

First Embodiment

FIGS. 1 to 3 each show a first embodiment of the present invention. FIG.1 is a cross-sectional view of a chief section of a vane compressor 1which is put in the resting condition. FIG. 2 is a cross-sectional viewof the chief section of the vane compressor 1 in the condition when anactivation mode is selected. FIG. 3 is a cross-sectional view of thechief section of the vane compressor 1 in the condition when aback-pressure supplying unit 13 and a position holding module 19 arereset.

The vane compressor 1 includes: a cylinder chamber 3; a rotor 5rotatably arranged in the cylinder chamber 3; vane grooves 7 provided inthe rotor 5 at equal intervals in a circumferential direction thereof;vanes 9 arranged in the vane grooves 7 in a way that the vanes 9 arecapable of protruding to, and retracting from, the cylinder chamber 3; avane back-pressure chamber 11 communicating with the bottom portions ofthe vane grooves 7, and configured to apply a back pressure to the vanes9; and a back-pressure supplying unit 13 configured to push up the vanes9 to a sliding surface of the cylinder chamber 3 by transmitting theback pressure to the vane back-pressure chamber 11 when an activationmode for rotating the rotor 5 is selected.

The back-pressure supplying unit 13 includes: a back-pressure cylinder15 communicating with the vane back-pressure chamber 11; an activationpiston 17 configured to generate the back pressure by moving in theback-pressure cylinder 15; an activation spring 21 configured to biasthe activation piston 17 in a back-pressure generating direction; and aposition holding module 19 configured to hold the activation piston 17in its resting position against the activation spring 21.

The position holding module 19 includes: an engagement part 25 providedbetween the activation piston 17 and a stopper member 23, and configuredto hold the activation piston 17 in a position where the activationpiston 17 rests before being pushed into the activation piston 17; anengagement spring 27 configured to bias the stopper member 23 in anengagement direction of the engagement part 25; and an electromagneticsolenoid 29 configured to release the engagement part 25 from itsengagement against the engagement spring 27.

The activation piston 17 is provided with a cam 31 configured to causethe stopper member 23 to retract against the engagement spring 27 whenthe activation piston 17 retracts due to a return pressure from the vaneback-pressure chamber 11 after the completion of the activation thereof.The engagement spring 27 causes the engagement part 25 to engage bypressing the stopper member 23 once retracted.

In addition, the low-pressure side of the back-pressure cylinder 15communicates with the inlet port 49.

The cylinder chamber 3 is almost elliptical, and is formed in a positioninside a front-side block (not illustrated), a cylinder block 33 and arear-side block (not illustrated). The rotor 5 is fixed to a rotor shaft35, and is arranged coaxial with the cylinder chamber 3. The vaneback-pressure chamber 11 is provided, for example, between thefront-side block (not illustrated) and the cylinder block 33, andbetween the rear-side block (not illustrated) and the cylinder block 33.The vane back-pressure chamber 11 communicates with the bottom portionsof the vane grooves 7 of the rotor 5. When the coolant starts to becompressed in response to the rotation of the rotor 5, the back pressurewhich occurs due to the discharge pressure is designed to work on thevane back-pressure chamber 11.

The cylinder block 33 is provided with two cylinder outlet ports 37 inits two portions. Each cylinder outlet port 37 is provided with a checkvalve 39. Each cylinder outlet port 37 communicates with the outlet port45 of the compressor housing 43 through an oil separator 41. The outletport 45 communicates with a condenser (not illustrated).

Two cylinder inlet ports 47 are provided in a position between thefront-side block (not illustrated) and the cylinder block 33, and in aposition between the rear-side block (not illustrated) and the cylinderblock 33. Each cylinder inlet port 47 communicates with the inlet port49 of the compressor housing 43. The inlet port 49 communicates with anevaporator (not illustrated). The compressor housing 43 is filled with apredetermined amount of oil 51. Part of this oil 51 is mixed with thecoolant.

The cylinder 15 in the back-pressure supplying unit 13 communicates withthe vane back-pressure chamber 11 through an oil passage 53. Theactivation spring 21 biases the activation piston 17 in theback-pressure generating direction (or the direction indicated by anarrow 71 in FIG. 2). In addition the low-pressure side of the cylinder15 (or the opposite side of the oil passage 53) communicates with thecylinder inlet ports 47 through the communicating passage 55.

The engagement part 25 of the position holding module 19 is constitutedof: a concave part 57 formed in the outer periphery of the activationpiston 17; and the tip portion of the stopper member 23. Theelectromagnetic solenoid 29 includes an electromagnetic coil 59 and anarmature 61. The armature 61 and the stopper member 23 are integratedinto a single unit. The engagement spring 27 biases the stopper member23 to the concave part 57 in the activation piston 17 with the armature61 being interposed in between.

In addition, after the cam 31 provided to the activation piston 17 comesinto contact with the tip of the stopper member 23, the cam 31 causesthe stopper member 23 to retract against the engagement spring 27 to aposition at which the stopper member 23 releases the engagement part 25from the engagement.

Next, descriptions will be provided for how the vane compressor 1operates. While the vane compressor 1 is in its resting status, as shownin FIG. 1, before the activation mode is selected, the rotor 1 rests,and the electromagnetic solenoid 29 is in the OFF state. The activationpiston 17 is held in its resting position with the tip portion of thestopper member 23 engaging with the concave part 57 of the activationpiston 17 while pressed by the engagement spring 27. Thereby, no backpressure is transmitted to the vane back-pressure chamber 11. As aresult, the vanes 9 retract back to the bottom portions of therespective vane grooves 7 due to the gravitation and the differentialpressure generated by the reverse rotation of the rotor.

Once the activation mode is selected, as shown in FIG. 2, theelectromagnetic solenoid 29 is turned on immediately. Once theelectromagnetic solenoid 29 is turned on, the stopper member 23 retractsfrom its engagement position, and the engagement part 25 is thusreleased is from the engagement. Once the engagement part 25 is releasedfrom the engagement, the activation spring 21 moves the activationpiston 17 in the back-pressure generating direction, and the hydraulicpressure (or the back pressure) is thus generated. Thereby, the backpressure is supplied to the vane back-pressure chamber 11 through theoil passage 53 as indicated by an arrow 73. In response to this, thevanes 9 are pushed up to, and brought into intimate contact with, thesliding surface of the cylinder chamber 3.

The electrical solenoid 29 is turned on momentarily when the activationmode is selected. After that, the electromagnetic solenoid 20 is turnedoff immediately.

After the rotor 5 starts to rotate with the vanes 9 being in intimatecontact with the sliding surface of the cylinder chamber 3, the vanes 9continue to be held in the state of being in intimate contact with thecylinder chamber 3 due to the centrifugal force generated by therotation of the rotor 5 and the discharge pressure (or the backpressure) supplied to the vane back-pressure chamber 11, as describedbelow, even when the electromagnetic solenoid 29 is turned off and theelectromagnetic coil 59 stops being excited.

Once, as shown in FIG. 3, the vanes 9 come into intimate contact withthe sliding surface of the cylinder chamber 3, the rotor 5 is driven torotate as indicated by the arrow 75, and the vane compressor 1 is thusactivated. The coolant is taken in through the inlet port 49 asindicated by the arrow 77, and is subsequently compressed. The resultantcoolant is discharged through the outlet port 45 as indicated by thearrow 79.

At this time, as described above, the electromagnetic solenoid 29 isturned off. The highly-pressurized oil (or the return pressure) whichoccurs due to the discharge pressure flows into the back-pressurecylinder 15 from the oil passage 53 as indicated by an arrow 81. Thehighly-pressurized oil (or the return pressure) moves the activationpiston 17 to its resting position against the activation spring 21. Inthe middle of the movement of the activation piston 17, the camoperates, and causes the stopper member 23 to retract against theengagement spring 27. Thereafter, when the concave part 57 in theactivation piston 17 moves to a position at which the concave part 57 isopposite to the tip of the stopper member 23, the stopper member 23engages with the concave part 57 due to the biasing force of theengagement spring 27. Thereby, the activation piston 17 is reset to itsresting position.

In addition, when, as described above, the activation piston 17 retractsdue to the discharge pressure, the compression of the activation spring21, the operation of the cam 31 and the compression of the engagementspring 27 are facilitated by the negative pressure applied to thelow-pressure side of the back-pressure cylinder 15 from thecommunicating passage 55 communicating with the inlet ports 47 on thelow-pressure side. Thereby, the activation piston 17 is assuredly resetto its resting position.

In the vane compressor 1, as described above, the start of the realcompression does not lag the activation of the compressor. That isbecause, before the rotor 5 starts to rotate, the back-pressuresupplying unit 13 transmits the back pressure to the vane back-pressurechamber 11, and the vanes 9 are thus pushed up to, and brought intointimate contact with, the sliding surface of the cylinder chamber 3. Asa result, the vane compressor 1 starts a compression operationimmediately after the vane compressor 1 is activated. This increases thecompression performance.

In addition, because the rotor 5 starts to rotate only after the vanes 9come into intimate contact with the sliding surface of the cylinderchamber 3, the vanes 9 do not chatter under the start-up operation,either.

Furthermore, when the activation piston 17 moves to its resting positionwith the return pressure being applied from the vane back-pressurechamber 11 after the completion of the activation, the cam 31 providedto the activation piston 17 causes the stopper member 23 to retractagainst the engagement spring 27 in the middle of the movement of theactivation piston 17. Subsequently, the engagement spring 27 causes theengagement part 25 to engage by pressing the retracted stopper member23. Thereby, the activation piston 17 is automatically reset to itsresting position at which the activation piston 17 rests before theactivation mode is selected. The activation piston 17 can be resetthereto without use of an external power or electric power.

Additionally, the electromagnetic solenoid 29 only needs to be on in amoment at which the engagement part 25 is released from the engagementby moving the stopper member 23 after the activation mode is selected.The electromagnetic solenoid 29 need not be operated after the vanecompressor 1 starts a compression operation and when the vane compressor1 resets the activation piston 17 to its resting position. For thisreason, the electromagnetic coil 59 consumes only a very small amount ofelectric power.

Moreover, because the low-pressure side of the back-pressure cylinder 15communicates with the cylinder inlet ports 47 through the communicatingpassage 55, the retraction of the activation piston 17 and the operationof the cam 31 are facilitated by the negative pressure applied to thelow-pressure side of the back-pressure cylinder 15 from the cylinderinlet ports 47. Thereby, the activation piston 17 is assuredly reset toits resting position.

Second Embodiment

FIGS. 4 to 6 each show a second embodiment of the present invention.FIG. 4 is a cross-sectional view of a chief section of a vane compressor101 which is put in the resting condition. FIG. 5 is a cross-sectionalview of the chief section of the vane compressor 101 which is activatedafter an activation mode is selected. FIG. 6 is a cross-sectional viewof the chief section of the vane compressor 101 in which a back-pressuresupplying unit 103 and an opening/closing module 109 are reset.

The vane compressor 101 includes: a cylinder chamber 3; a rotor 5rotatably arranged in the cylinder chamber 3; vane grooves 7 provided inthe rotor 5 at equal intervals in a circumferential direction of therotor 5; vanes 9 arranged in the vane grooves 7 in a way that the vanes9 are capable of protruding to, and retracting from, the cylinderchamber 3; a vane back-pressure chamber 11 communicating with the bottomportions of the vane grooves 7, and configured to apply a back pressureto the vanes 9; and a back-pressure supplying unit 103 configured topush up the vanes 9 to a sliding surface of the cylinder chamber 3 bytransmitting the pressure to the vane back-pressure chamber 11 when anactivation mode for driving to rotate the rotor 5 is selected.

The back-pressure supplying unit 103 includes: a high-pressure tank 105communicating with the vane back-pressure chamber 11, and filled withhighly-pressurized oil (or a fluid) 51 mixed with a coolant gas; asolenoid valve (valve) 107 configured to allow and shut off a flow ofthe oil 51 between the vane back-pressure chamber 11 and thehigh-pressure tank 105; an opening/closing module 109 configured to openthe solenoid valve 107, and thus to cause the pressure (or the backpressure) to be transmitted from the high-pressure tank 105 to the vaneback-pressure chamber 11, once the activation mode is selected.

The opening/closing module 109 includes: a stopper spring 111 configuredto close the solenoid valve 107; and an electromagnetic solenoid 113configured to cause the back pressure to be transmitted from thehigh-pressure tank 105 to the vane back-pressure chamber 11 by openingthe solenoid valve 107 against the stopper spring 111 once theactivation mode is selected.

While the following descriptions are provided, functional parts andfunctional members which are the same as those of the vane compressor 1according to the first embodiment are denoted by the same referencenumerals. Duplicated descriptions will be omitted. The descriptionswhich have been provided for the first embodiment will be referred towhenever deemed necessary.

The high-pressure tank 105 in the back-pressure supplying unit 103communicates with the vane back-pressure chamber 11 through an oilpassage 53. The solenoid valve 107 is provided in a location at whichthe high-pressure tank 105 is opened to, and closed from, the oilpassage 53.

The stopper spring 111 in the opening/closing module 109 is arranged ina direction in which the solenoid valve 107 is opened against thestopper spring 111.

In addition, the electromagnetic solenoid 113 includes anelectromagnetic coil 115 and an armature 117. The armature 117 isconnected to the solenoid valve 107 with a shaft 119 being interposed inbetween.

Next, descriptions will be provided for how the vane compressor 101, theback-pressure supplying unit 103 and the opening/closing module 109operate.

As shown in FIG. 4, while the vane compressor 101 is in a resting statusuntil the activation mode is selected, the electromagnetic solenoid 113is turned off. The solenoid valve 107 is stopped by the inner pressureof the high-pressure tank 105 and the biasing force of the stopperspring 111. No back pressure is transmitted to the vane back-pressurechamber 11. Accordingly, the vanes 9 retract back to the bottom portionsof the vane grooves 7 due to the gravitation and the differentialpressure generated by the reverse rotation of the rotor.

Once the activation mode is selected, as shown in FIG. 5, theelectromagnetic solenoid 113 is turned on, and the solenoid valve 107 isthus opened against the stopper spring 111. Once the solenoid valve 107is opened, the hydraulic pressure (or the back pressure) is suppliedfrom the high-pressure tank 105 to the vane back-pressure chamber 11through the oil passage 53 as indicated by an arrow 73. The vanes 9 arepushed up to, and brought into intimate contact with, the slidingsurface of the cylinder chamber 3 by this back pressure.

The electromagnetic solenoid 113 is turned on momentarily when theactivation mode is selected. After that, the electromagnetic solenoid113 is immediately turned off.

After the rotor 5 starts to rotate with the vanes 9 being in intimatecontact with the cylinder chamber 3, the vanes 9 continue to be held inthe state of being in intimate contact with the cylinder chamber 3 dueto the centrifugal force generated by the rotation of the rotor 5 andthe discharge pressure (or the back pressure) supplied to the vaneback-pressure chamber 11, as described below, even when theelectromagnetic solenoid 113 is turned off.

Once, as shown in FIG. 6, the vanes 9 come into intimate contact withthe cylinder chamber 3, the rotor 5 is driven to rotate as indicated byan arrow 75, and the vane compressor 101 is thus activated. The coolantis taken in through the inlet port 49 as indicated by an arrow 77, andis subsequently compressed. The resultant coolant is discharged throughthe outlet port 45 as indicated by the arrow 79.

At this time, as described above, the electromagnetic solenoid 113 isturned off. The highly-pressurized oil (or the return pressure) whichoccurs due to the discharge pressure flows from the oil passage 53 asindicated by an arrow 81. The solenoid valve 107 is opened against thestopper spring 111, and the highly-pressurized oil (or the returnpressure) thus flows into the high-pressure tank 105 as indicated by anarrow 83. Subsequently, once the pressure of the high-pressure tank 105becomes equal to the pressure of the vane back-pressure chamber 11, thesolenoid valve 107 is stopped by the stopper spring 111, and is thusreset to its resting position at which the solenoid valve 107 is locatedbefore the activation mode is selected.

In the vane compressor 101, as described above, the start of the realcompression does not lag the activation of the compressor. That isbecause, before the rotor 5 starts to rotate, the back pressure istransmitted to the vane back-pressure chamber 11 from the high-pressuretank 105, and the vanes 9 are thus pushed up to, and brought intointimate contact with, the sliding surface of the cylinder chamber 3. Asa result, the vane compressor 101 starts a compression operationimmediately after the vane compressor 101 is activated. This increasesthe compression performance.

In addition, because the rotor 5 starts to rotate only after the vanes 9come into intimate contact with the sliding surface of the cylinderchamber 3, the vanes 9 do not chatter under the start-up operation,either.

Furthermore, the solenoid valve 107 is configured to be opened againstthe stopper spring 111. For this reason, after the vane compressor 101starts a compression operation, the solenoid valve 107 is automaticallyopened against the stopper spring 111 by the return pressure from thevane back-pressure chamber 11, and the high-pressure tank 105 is filledwith the oil. Subsequently, once the pressure of the high-pressure tank105 becomes equal to the pressure of the vane back-pressure chamber 11,the solenoid valve 107 is closed by the stopper spring 111, and is resetto its resting position. The solenoid valve 107 is reset thereto withoutuse of an external force or electric power.

Additionally, the electromagnetic solenoid 113 is operated only in amoment at which the solenoid valve 107 is opened after the activationmode is selected. The electromagnetic solenoid 113 need not be operatedafter the vane compressor 1 starts a compression operation and when thevane compressor 1 resets the solenoid valve 107 to its resting position.For this reason, the electromagnetic coil 115 consumes only a very smallamount of electric power.

(Other Embodiments Included in the Scope of Claims)

It should be noted that the present invention shall not be construed asbeing limited to only the foregoing embodiments, and that the presentinvention can be variously modified within the technical scope of thepresent invention.

In addition, the vane compressor according to the present invention isapplicable to any type of scheme for inputting driving torque. Forexample, the present invention is capable of being operated as anintegrated motor-driven compressor obtained by assembling the vanecompressor and an electric motor together, and as a pulley-drivencompressor driven by driving torque inputted through a pulley.

Furthermore, the application of the vane compressor according to thepresent invention is not limited to a cooling system in a vehicleair-conditioning apparatus.

The entire contents of the Japanese Patent Application No. 2007-208016(filed on Aug. 9, 2007) are incorporated in the description byreference.

1. A vane compressor (1, 101), comprising: a cylinder chamber (3); arotor (5) rotatably arranged in the cylinder chamber (3); vane grooves(7) provided in the rotor (5) at equal intervals in a circumferentialdirection of the rotor (5); vanes (9) arranged in the vane grooves (7)in a manner such that the vanes (9) are capable of protruding to, andretracting from, the cylinder chamber (3); a vane back-pressure chamber(11) communicating with bottom portions of the vane grooves (7), andconfigured to apply a back pressure to the vanes (9); and aback-pressure supplying unit (13) configured to push up the vanes is (9)to a sliding surface of the cylinder chamber (3) by transmitting theback pressure to the vane back-pressure chamber (11) when an activationmode for rotating the rotor (5) is selected.
 2. The vane compressor (1)according to claim 1, wherein the back-pressure supplying unit (13)comprises: a back-pressure cylinder (15) communicating with the vaneback-pressure chamber (11); an activation piston (17) configured togenerate the back pressure by moving in the back-pressure cylinder (15);an activation spring (21) configured to bias the activation piston (17)in a back-pressure generating direction; and a position holding module(19) configured to hold the activation piston (17) in its restingposition against the activation spring (21).
 3. The vane compressor (1)according to claim 2, wherein the position holding module (19)comprises: an engagement part (25) provided between the activationpiston (17) and a stopper member (23), and configured to hold theactivation piston (17) in its resting position; an engagement spring(27) configured to bias the stopper member (23) in an engagementdirection of the engagement part (25); and an electromagnetic solenoid(29) configured to release the engagement part (25) from its engagementagainst the engagement spring (27).
 4. The vane compressor (1) accordingto claim 3, wherein the activation piston (17) is provided with a cam(31) configured to cause the stopper member (23) to retract against theengagement spring (27) when the activation piston (17) retracts due to areturn pressure which is transmitted from the vane back-pressure chamber(11) after the completion of the activation thereof; and the engagementspring (27) is configured to cause the engagement part (25) to engage bypressing the stopper member (23) once retracted.
 5. The vane compressoraccording to claim 2, wherein a low-pressure side of the back-pressurecylinder (15) communicates with the inlet port (49).
 6. The vanecompressor according to claim 3, wherein a low-pressure side of theback-pressure cylinder (15) communicates with the inlet port (49). 7.The vane compressor according to claim 4, wherein a low-pressure side ofthe back-pressure cylinder (15) communicates with the inlet port (49).8. The vane compressor (101) according to claim 1, wherein theback-pressure supplying unit (103) comprises: a high-pressure tank (105)communicating with the vane back-pressure chamber (11), and filled witha highly-pressurized fluid (51); a valve (107) configured to allow andshut off a flow of the fluid (51) between the vane back-pressure chamber(11) and the high-pressure tank (105); and an opening/closing module(109) configured to open the valve (107), and thus to cause the backpressure to be transmitted from the high-pressure tank (105) to the vaneback-pressure chamber (11), once the activation mode is selected.
 9. Thevane compressor (101) according to claim 8, wherein the opening/closingmodule (109) comprises: a stopper spring (111) configured to close thevalve (107); and an electromagnetic solenoid (113) configured to causethe back pressure to be transmitted from the high-pressure tank (105) tothe vane back-pressure chamber (11) by opening the valve (107) againstthe stopper spring (111) once the activation mode is selected.